The initial nuclear strikes against Japan and South Korea kill 1.5million people, while another 1.4million people die in the US after New York.
The year is 2023 and the world is still recovering from the devastating North Korean nuclear attacks on Japan, South Korea and the United States three years before.
Almost 3million people died as soon as the bombs went off, causing a tornado of flame to rip through Tokyo, levelling Manhattan, and wiping the city of Jupiter, Florida, off the map - after narrowly missing Mar-a-Lago.
This is the dire future imagined by Dr Jeffrey Lewis, one of the world's foremost experts on the North Korean nuclear programme, as he paints a picture of what could happen should the peace talks between Donald Trump and Kim Jong-un fail.
Dr Lewis, who works at the the Middlebury Institute of International Studies, makes the prediction in his novel, The 2020 Commission Report on the North Korean Nuclear Attacks Against the United States, in which he imagines himself analysing the events leading up to the strikes and the harrowing fallout.
Dr Lewis told Mail Online that he decided to write the book after struggling to get people to take the threat of nuclear war seriously in his everyday research.
He said: 'North Korea says it is willing to use nuclear weapons and that's what I was never able to convey in nonfiction, no matter what I tried, I could never really effectively express it.
Nuclear war is an unimaginable horror so we discount the possibility of it happening, even though it actually happened to people who are alive now.
'I don't think the risk on any given day is very high, but this is a risk that we have decided to run forever, day after day after day, and the risk on a day to day basis - even if it is low - is much higher than it needs to be.'
In his book, the nuclear strikes take place after peace talks between Trump and Kim collapse, with the President returning to personal attacks on the dictator via Twitter while his advisers ratchet up pressure on his regime with aggressive military drills on the border.
This culminates in North Korea accidentally shooting down a South Korean plane filled with hundreds of civilians, including more than 100 children, after mistaking it for an American bomber.
South Korea retaliates with a missile strike of its own, setting off a chain of events that quickly spirals into a nuclear conflict which none of the parties were intending to cause.
This event is based on the real-life shootdown of Korean Airlines flight KL007 which was destroyed by the Soviets in 1983, raising fears of a war between America and Russia.
Believing that an American invasion is imminent, Kim Jong-un fires nukes at South Korea and Japan, hoping to halt American troops in their tracks and force Trump to the negotiating table.
The initial attack kills 1.5million people in Tokyo, Seoul, Busan and other cities across Japan and South Korea, incinerating them in a blinding flash of light.
In fact, Kim's strike is huge miscalculation based on bad information and a rogue tweet from President Trump. American troops are not about to invade, but constant threats and military drills have convinced him that his country is about to be overrun.
While this scenario may seem unlikely, Dr Lewis argues that it is not as far-fetched as most people would like to believe - pointing to Saddam's actions before the US invasion of Iraq which ultimately saw him killed.
'One of the major question the US had leading up to the war was: why didn't Saddam realise it was over for him? Why didn't he realise this catastrophic war was coming and that it would end with his death? And the answer is that Saddam didn't seriously consider the possibility that the US would do anything more than seize the southern third of the country and set up an autonomous state just as they had in practice done in the north.
'It never occurred to him take seriously the possibility that the US would go into Baghdad.
'It's just such a monumental miscalculation - his life depended on him not making that mistake, and he still made it. So it's not hard for me to imagine Kim making the same mistake, or a similar kind of mistake, by concluding that he could use nuclear weapons to halt the United States invasion.
'Everyone thinks that view is crazy but that's literally why countries acquire nuclear weapons. They acquire them as invasion insurance.
'So it's certainly not a strange thing for Kim to think and it's not as strange as the things Saddam thought.'
Ironically, the nuclear strikes that Kim hoped would save him actually prompt the very attack he was dreading.
Seeing the American military heading straight for his borders, the young dictator reaches for his last line of defence - a dozen long-range nukes fired at the mainland United States.
It is thought that Kim already possesses such weapons, having successfully tested several Intercontinental Ballistic Missiles last year, which could be equipped with nuclear warheads.
Of course, Kim ends up dead - shooting himself in the head as special forces close in on his bunker, while his regime is dismantled as the American military rolls over North Korea in a matter of days, but not before his nukes can get airborne.
Some of these missiles either miss their targets or disintegrate, but seven manage to evade US defence systems before slamming into Hawaii, Florida, northern Virginia, and New York with horrific consequences.
In total, 1.4million perish instantly, while millions more receive third-degree radiation burns. Children stumble through the streets with charred flesh hanging from their arms in scenes reminiscent of the Vietnam war, while hospitals are overloaded with the dead and dying.
Black rain even begins falling from the sky as ash and dust kicked up from the bombs mixes with clouds formed by the explosion.
While the vision may seem over-the-top, in fact Dr Lewis drew on real-life testimonies from the US nuclear attacks on Japan while writing.
He said: 'It was very important to me when I sat down to write the survivor stories, that I didn't want to just make them up, so I used real stories [from Hiroshima].
'What I had noticed about them was that because people have foreign names and the place names are foreign and the grammar and phrasing is a bit stilted, people are able to hold those stories at arms length and say "those are things that happen to other people. That's a thing that happens someplace else to someone else and that's not a thing that could happen to us."
'I tried very hard to take those stories and curate them and put them in context and make them stories which might be more familiar to an American reader.'
Another 4.5million people perish across America in the ensuing years from their wounds, while millions more a left living with compromised immune systems as the result of radiation exposure.
This places a huge strain on the healthcare system, and causes the first recorded outbreak of plague in New York.
Dr Lewis's message is that such a thing could happen, such a thing might even be likely to happen, if we are not careful enough about preventing it.
While talks between Trump and Kim are encouraging, he fears that the President is not being realistic enough with his aims.
Dr Lewis firmly believes that Kim is never going to give up his nuclear stockpile, so Trump needs to refocus and instead insist on a reduction in the number of weapons, while maintaining some form of dialogue with the North.
The worst outcome, in his opinion, would be for either nation to start increasing their nuclear stockpiles again, while returning to the baiting and name-calling of last year that saw branded Kim 'little rocket man' and Trump called a 'mentally deranged US dotard'.
He added: 'I understand and appreciate the deterrent value of nuclear weapons on a day-to-day basis, I can see why as a short term thing they are desirable, and it's hard to imagine just giving them up.
'But eventually that system is going to break down, so I think we have to take seriously the prospect of moving to a world in which these weapons are not central to our security policy.
'The details of how we do that are less important than simply recognising that we are living on borrowed time. This is like a family trust and we're eventually going to run out of money, so we should start planning for that future.'
Ultimately, the goal should be to eliminate the threat of nuclear war entirely, he says.
'When I talk to people it seems like such a big task: how do you eliminate nuclear weapons, it's a big ask,' he says.
'People get cynical and say: "Well when we have a bomb go off, that's what it'll take for change." And I don't agree with that. We've already had two go off, we know what these weapons do, we know people are imperfect.
'In the book, I wanted to make it clear that even if we kill a million people, there's no guarantee that we will learn the lesson that are already in front of us, so just learn them.'
The 2020 Commission Report on the North Korean Nuclear Attacks Against the United States is available to buy now from Penguin